diff --git a/diff-tree.c b/diff-tree.c
index f3280a13ee..7148323348 100644
--- a/diff-tree.c
+++ b/diff-tree.c
@@ -284,14 +284,15 @@ int main(int argc, const char **argv)
 		}
 		usage(diff_tree_usage);
 	}
-	if (diff_options.output_format == DIFF_FORMAT_PATCH)
-		diff_options.recursive = 1;
 
 	if (combine_merges) {
 		diff_options.output_format = DIFF_FORMAT_PATCH;
 		ignore_merges = 0;
 	}
 
+	if (diff_options.output_format == DIFF_FORMAT_PATCH)
+		diff_options.recursive = 1;
+
 	diff_tree_setup_paths(get_pathspec(prefix, argv));
 	diff_setup_done(&diff_options);